Inner seal for cv joint boot

ABSTRACT

A combined CV joint boot and inner seal includes a boot portion having a first end and a second end and having a shaft sealing portion at the first end for sealing with a first shaft of the CV joint. A front can sealing portion is positioned at the second end of the boot portion. An inner seal portion extends generally inwardly towards the CV joint longitudinal axis to block lubricant from migrating into the interior of the boot portion.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 11/917,266,filed Jun. 13, 2008, which is a National Stage of InternationalApplication No. PCT/CA2006/000966, filed Jun. 13, 2006, which claims thebenefit of Provisional Application No. 60/689,536, filed Jun. 13, 2005.These applications are incorporated herein by reference in theirentirety.

FIELD OF THE INVENTION

The present invention relates to CV joint boots, and more particularlythe invention relates to an inner seal for protecting a CV joint boot.

BACKGROUND OF THE INVENTION

A CV joint is a structure that permits two shafts to connect to eachother. In particular a CV joint can be used when transferring rotationalenergy from a first shaft to a second shaft, when a non-zero angleexists between the two shafts, or when the shafts are expected to moverelative to each other during use. A typical application for a CV jointis in a passenger vehicle, however, they are also used in numerous otherapplications.

A CV joint typically includes a bearing, comprising an inner race, anouter race, a plurality of rolling elements positioned between the innerand outer races, and a cage which retains the balls. The first shaft ismounted to the inner race, and typically extends through an aperture inthe inner race. The second shaft is mounted to the outer race. On oneside of the bearing, a flexible boot typically mounts between the firstshaft and a member called a front can, which itself is connected to theouter race. The flexible boot, typically referred to as a CV joint boot,protects the other side of the bearing from contamination by debris ordirt from the surrounding environment during use. On the other side ofthe bearing there is some structure that protects the bearing fromcontamination by debris or dirt from the surrounding environment duringuse.

Lubricant is typically used in the bearing to inhibit wear of therolling elements. During use of the CV joint, however, some lubricantcan migrate out from the bearing and eventually can make its way intothe interior of the CV joint boot. Depending on a variety of factors,the presence of enough lubricant in the boot can overstress the boot ata sufficiently high rotational speed of the joint, eg greater than 5000rpm, and can ultimately lead to tearing of the boot during use.

Consequently, there is a need for a way of inhibiting the migration ofbearing lubricant into the interior of the CV joint boot during use ofthe CV joint.

SUMMARY OF THE INVENTION

In a first aspect, the invention is directed to an inner seal forprotecting a CV joint boot for a CV joint. The CV joint includes abearing, a back sealing means and a front can. The bearing operativelyconnects a first shaft and a second shaft. The bearing has an inner raceand an outer race and has a front and a back. The first shaft isconnected to the inner race. The second shaft is connected to the outerrace. The front can is connected to the outer race. The back sealingmeans seals against leakage of lubricant from the back of the bearing.The CV joint boot seals with the front can. The CV joint boot has aninterior. The inner seal comprises an inner seal body having a front cansealing portion for sealing with the front can to inhibit the migrationof lubricant from the bearing into the interior of the CV joint boot.The inner seal body has a shaft sealing portion for sealing with thefirst shaft to inhibit the migration of lubricant from the bearing intothe boot. The inner seal body has a shield portion that extends betweenthe front can sealing portion and the shaft sealing portion.

In a second aspect, the invention is directed to a combined CV jointboot and inner seal for mounting to a CV joint. The CV joint includes abearing, a back sealing means and a front can. The CV joint has a CVjoint longitudinal axis. The bearing operatively connects a first shaftand a second shaft. The bearing has an inner race and an outer race andhas a front and a back. The first shaft is connected to the inner race.The second shaft is connected to the outer race. The front can isconnected to the outer race. The back sealing means seals againstleakage of lubricant from the back of the bearing. The combined CV jointboot and inner seal comprises a boot portion having a first end and asecond end and having a shaft sealing portion at the first end forsealing with the first shaft. The boot portion has an interior. Thecombined CV joint boot and inner seal further comprises a front cansealing portion for sealing with the front can. The front can sealingportion is positioned at the second end of the boot portion. Thecombined CV joint boot and inner seal further comprises an inner sealportion. In use, the inner seal portion extends generally inwardlytowards the CV joint longitudinal axis from the front can sealingportion to block lubricant from migrating into the interior of the bootportion.

In a third aspect, the invention is directed to an inner seal forprotecting a CV joint boot for a CV joint. The CV joint includes abearing, a back sealing means and a front can. The CV joint has a CVjoint longitudinal axis. The bearing operatively connects a first shaftand a second shaft. The bearing has an inner race and an outer race andhas a front and a back. The first shaft is connected to the inner race.The second shaft is connected to the outer race. The back seating meansseals against leakage of lubricant from the back of the bearing. Thefront can is connected to the outer race. The front can has an outersurface and an inner surface. The CV joint boot seals with the frontcan. The inner seal comprises an inner seal body having a front cansealing portion for forming a connection with the front can and forsealing with the inner surface of the front can to inhibit the migrationof lubricant therebetween. In use, the connection between the inner sealand the front can is entirely separate from the connection between thefront can and the outer race. In use, the inner seal body extends fromthe front can sealing portion generally inwardly towards the CV jointlongitudinal axis to block lubricant from migrating into the interior ofthe CV joint boot.

In a fourth aspect, the invention is directed to a combination for usewith a CV joint. The CV joint includes a bearing and a back sealingmeans and has a CV joint longitudinal axis. The bearing operativelyconnects a first shaft and a second shaft. The bearing has an inner raceand an outer race and has a front and a back. The first shaft isconnected to the inner race. The second shaft is connected to the outerrace. The back sealing means seals against leakage of lubricant from theback of the bearing. The combination includes a front can, wherein thefront can is connectable to the outer race. The front can has an outersurface and an inner surface. The front can and a combined CV joint bootand inner seal. The front can has a crimping portion. The combined CVjoint boot and inner seal includes a boot portion having a first end anda second end and having a shaft sealing portion at the first end forsealing with the first shaft. The boot portion has an interior. Thecombined CV joint boot and inner seal further includes a front cansealing portion for forming a seal with the front can. The front cansealing portion is positioned at the second end of the boot portion. Thefront can sealing portion includes a flange portion. The crimpingportion is crimped over the flange portion. The combined CV joint bootand inner seal further includes an inner seal portion. The inner sealportion extendible generally inwardly towards the CV joint longitudinalaxis from the front can sealing portion to block lubricant frommigrating into the interior of the boot portion.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described by way of example only withreference to the attached drawings in which:

FIG. 1 a is a sectional side view of an inner seal for a CV joint inaccordance with an embodiment of the present invention;

FIG. 1 b is a magnified sectional side view of a portion of the CV jointand inner seal shown in FIG. 1 a;

FIG. 1 c is another magnified sectional side view of a portion of the CVjoint and inner seal shown in FIG. 1 a;

FIG. 2 a is a sectional side view of a combined boot and inner seal fora CV joint in accordance with an alternative embodiment of the presentinvention, shown at an intermediate stage of assembly;

FIG. 2 b is a sectional side view of the combined boot and inner sealand CV joint shown in FIG. 2 a, as a complete assembly;

FIG. 3 is a sectional side view of a combined boot and inner seal for aCV joint in accordance with another alternative embodiment of thepresent invention;

FIG. 4 is a sectional side view of a combined boot and inner seal for aCV joint in accordance with yet another alternative embodiment of thepresent invention;

FIG. 5 is a sectional side view of an inner seal for a CV joint inaccordance with yet another alternative embodiment of the presentinvention; and

FIG. 6 is a sectional side view of the inner seal and CV joint shown inFIG. 5, shown at an intermediate stage of assembly.

DETAILED DESCRIPTION OF THE INVENTION

Reference is first made to FIGS. 1 a-1 c, which illustrate a CV joint 10with a CV joint boot 12 and an inner seal 14 made in accordance with afirst embodiment of the present invention.

The CV joint 10 is used to operatively connect a first shaft 16 to asecond shaft (not shown). During use, the first and second shafts mayextend at a non-zero angle with respect to each other (not shown).Furthermore, in use, they may move longitudinally relative to eachother. One or both of these conditions may occur either intermittentlyor constantly. The CV joint 10 may be configured to operate under one ormore of these conditions.

The CV joint 10 has a longitudinal axis A and includes a bearing 20, aback sealing means 22 and a front can 24. The bearing 20 includes aninner race 26, an outer race 28, a plurality of roller elements 30 and acage 31. The bearing 20 also has a front 32 and a back 33. The rollerelements 30 operatively connect the inner and outer races 26 and 28,while permitting the races 26 and 28 to move longitudinally and/orangularly relative to each other. The roller elements 30 may be, forexample, spherical.

Each roller element 30 sits in part in a pocket 34 in the inner race 26and in part in a pocket 36 in the outer race 28. The pockets 34 and 36capture each roller element 30 so that rotational force from the innerrace is transmitted to the outer race through the roller elements 30,and vice versa. The cage 31 captures the roller elements to prevent themfrom escaping from the bearing 20 in the longitudinal direction.

The inner race 26 has a central aperture 38 therethrough which receivesthe first shaft 16. The first shaft 16 is received in the aperture 38 insuch a manner that rotational force from the first shaft 16 istransmitted to the inner race 26 and vice versa. Preferably force can betransmitted without slippage occurring between the two. For example, theend of the first shaft 16 may be splined and the aperture 38 may beprovided with a complementary spline for receiving the first shaft 16.Alternatively, the first shaft 16 and the aperture 38 may include akeyway (not shown) for receiving a key (not shown) to effect transfer offorce therebetween.

A snap ring 40 may be positioned in a groove 42 on the first shaft 16 toassist in retaining the first shaft 16 and the inner race 26 connectedtogether.

The outer race 28 is connected to the second shaft (not shown). Theconnection may be by any means that permits transfer of rotational forcebetween the two, preferably without slippage.

The boot 12 and the inner seal 14 have a longitudinal axis B. When theboot 12 and inner seal 14 are mounted on the CV joint 10, thelongitudinal axis B may be coaxial with the axis A.

Lubricant 44 is used to lubricate the roller elements 30. The backsealing means 22 may be filled with lubricant 44 to provide a supply oflubricant 44 during use of the CV joint 10. The back sealing means 22seals with the outer race 28 on the back 33 of the bearing 20 to inhibitthe leakage of lubricant 44 therebetween, thereby inhibiting leakagelubricant 44 from the interior of the CV joint 10 to the exteriorenvironment. Additionally, the back sealing means 22 and the outer race28 seal together to inhibit the passage of dirt and debris therebetween,ie. into the interior of the CV joint 10 from the exterior environment.Dirt and debris can be present in the exterior environment if, forexample, the CV joint is used in the drivetrain of a passenger vehiclesuch as a car, a van or a pick up truck.

The back sealing means 22 may be made from any suitable material such asa corrosion resistant metal (eg. Galvanized steel, stainless steel).

The configuration of the back sealing means 22 may alternatively bedifferent than that which is shown in FIG. 1 a. The back sealing means22 may alternatively be any suitable structure that seals with respectto the bearing 20 sufficiently to inhibit, and preferably prevent,leakage of lubricant 44 out to the exterior environment and to inhibit,and preferably prevent leakage of dirt and debris into the interior ofthe CV joint 10.

The front can 24 is connected to the outer race 28 and provides astructure to which one end of the CV joint boot 12 can mount. The frontcan 24 forms a seals with the outer race 28 to inhibit leakage oflubricant 44 out of the CV joint 10, and to inhibit entry of dirt anddebris into the CV joint from the exterior environment. It is possiblefor the front can 24 to be connected directly to the outer race 28, asshown in FIG. 1 a, or alternatively for the front can 24 to be connectedindirectly to the outer race 28, by means of some intermediate piece orstructure (not shown).

The front can 24 has a bearing sealing portion 48, an optional shieldportion 50, a boot sealing portion 52 and an inner seal sealing portion54. The bearing sealing portion 48 is used to form a seal between thefront can 24 and the bearing 20 to inhibit leakage of lubricant 44 fromthe bearing to the exterior environment, and to inhibit entry of dirtand debris from the exterior environment into the CV joint 10, and inparticular into the bearing 20. In an embodiment as shown in FIG. 1 awherein the front can 24 directly contacts the outer race 28, thebearing sealing portion 48 may contact a portion of the outer edgesurface of the outer race 28, and may extend generally inwards towardsthe axis A, over some portion of the front 32 of the bearing 20. Forexample, the bearing sealing portion 48 may extend over the entirefront-facing portion of the outer race 28. A suitable adhesive may beused to fix the bearing sealing portion 48 to the bearing 20.Alternatively, the bearing sealing portion 48 may have any othersuitable configuration for mounting the front can 24 to the bearing 20and may mount to and seal with the bearing 20 in any other way, ego bymeans of a mechanical connection without adhesive.

The shield portion 50 may be directly connected to the bearing sealingportion 48. The shield portion 50 is configured to retard the progressof lubricant 44 migrating in a frontward direction towards the CV jointboot 12. For example, in the embodiment shown in FIG. 1 a, the shieldportion 50 extends in a direction that is longitudinally frontward andgenerally inward towards the axis A. For example, the shield portion 50may be generally frusto-conical with a radial distance to the axis Athat decreases as the shield portion 50 extends longitudinallyfrontwards.

During use when the CV joint 10 rotates, lubricant 44 in the bearing 20is generally urged outwardly away from the axis A. Accordingly, it isexpected that at least some portion of the lubricant 44 will be urgedtoward the inner surface shown at 56, of the outer race 28. From theresome lubricant 44 will migrate out of the bearing 20. As a result of theurging of the lubricant 44 is urged generally outwardly away from theaxis A by the rotation of the CV joint 10. Because the shield portion 50extends generally inwardly towards the axis A in a longitudinaldirection away from the bearing 20, it inhibits lubricant 44 frommigrating along its inner surface.

In an alternative embodiment that is not shown the front can may bewithout a shield portion. The front can could, for example, have a bootsealing portion and a inner seal sealing portion could be connecteddirectly to the bearing sealing portion 48. As another alternative (notshown), the boot sealing portion and an inner seal sealing portion maybe connected by a portion that extends longitudinally at constant radialdistance to the axis A, or at increasing radial distance to the axis Ain a direction away from the bearing 20. In these alternativeembodiments, it will be understood that the resistance by the front canto migration of lubricant 44 will be reduced relative to the embodimentshown in FIG. 1 a.

The boot sealing portion 52 of the front can 24 receives one end of theCV joint boot 12. The boot sealing portion 52 of the front can 24 may bepositioned on the outer surface of the front end of the front can 24.The inner seal sealing portion 54 of the front can 24 may be positionedon the inner surface of the front end of the front can 24. Thus, theboot sealing portion 52 of the front can 24 and the inner seal sealingportion 54 of the front can 24 may be positioned at the samelongitudinal position, occupying the outer and inner surfaces of thesame portion of the front can 24. However, it is alternatively possiblefor the two sealing portions 52 and 54 to be at different longitudinalpositions relative to each other.

Reference is made to FIGS. 1 b and 1 c, which show a magnified view ofthe front end of the front can 24. The front can 24 may be provided witha projection 58 on the front can inner surface shown at 60, and acorresponding channel 62 on the front can outer surface, shown at 64.The projection 58 and channel 62 may extend partially or completelyabout the perimeter of the inner surface 60 of the front can 24. Theprojection 58 and channel 62 may be continuous around the perimeter ofthe front can 24. Alternatively, they may be made up of a plurality ofspaced projection I channel segments that extend around the perimeter ofthe front can 24. The projection 58 and channel 62 are described furtherbelow.

The front can 24 may be made from any suitable material such as acorrosion resistant metal (eg. Galvanized steel, stainless steel).

Referring to FIG. 1 a, the CV joint boot 12 protects the CV joint 10from damage from dirt and debris from the surrounding environment. Theboot 12 includes a boot body 66, which has a first end 68 and a secondend 70. The boot body 66 may comprise a bellows portion to permit theboot 12 to flex, elongate or shorten as necessary during operation ofthe CV joint 10.

A shaft sealing portion 72 may be positioned at the first end 68. Theshaft sealing portion 72 seals with the first shaft 16, to inhibit theentry of dirt and debris from the outside environment therebetween,thereby inhibiting the entry of dirt and debris from the outsideenvironment into the interior of the CV joint 10.

The shaft 16 may be provided with a circumferential channel 74, whichmates with a corresponding projection 76 on the shaft sealing portion 72of the boot 12. The channel 74 and projection 76 cooperate to positionthe first end 68 of the boot 12 at a selected longitudinal position, andto assist in retaining the first end 68 of the boot 12 in the saidposition during operation of the CV joint 10. A holding means 78, suchas an oetiker clamp may be used to hold the first end 68 of the boot 12to the shaft 16. Alternatively, or additionally, a suitable adhesive maybe applied between the shaft sealing portion 72 and the shaft 16. Theadhesive could provide any suitable portion of the sealing performancebetween the shaft sealing portion. 72 and the shaft 16.

A front can sealing portion 80 may be positioned at the second end 70 ofthe boot 12. The front can sealing portion 80 seals with the front can24 to inhibit entry of dirt and debris therebetween, thereby inhibitingentry of dirt and debris into the interior of the CV joint 10. The frontcan sealing portion 80 may include a projection 82, which mates with thechannel 62 on the front can 24. The projection 82 cooperates with thechannel 62 to position the second end 70 of the boot 12 at a selectedlongitudinal position, and to assist in retaining the second end 70 ofthe boot 12 in the said position during operation of the CV joint 10.Thus, the projection 82 and channel 62, and the projection 76 andchannel 74 all cooperate together to fix both ends of the CV joint boot12 in selected positions, so that the operating parameters for the boot12 can be predicted to some extent based on the operating parameters ofthe CV joint 10.

A second holding means 84, such as an oetiker clamp, may be used to holdthe boot 12 to the front can 24. Additionally, or alternatively, asuitable adhesive may be used to adhere the front can sealing portion 80on the boot 12 to the front can 24. The adhesive may itself formsubstantially all of the sealing function between the boot 12 and thefront can 24. An example of an adhesive that can be used is a siliconeadhesive commonly referred to as a room temperature vulcanizing (RTV)silicone, which is an oxime silicone. For example, a suitable adhesiveis provided by LOCTITE™ under the name “Flange Sealant” LOCTITE 5999™,part number 21744.

The boot 12 may be made by any suitable process, and may be made fromany suitable material, such as a suitable elastomeric material, topermit repeated flexure of the bellows portion during operation of theCV joint 10 without substantially fatiguing the boot 12.

The inner seal 14 inhibits migration of lubricant 44 from the bearing 20into the interior of the boot 12, thereby protecting the boot 12. Theinner seal 14 has an inner seal body 86, which has a front can sealingportion 88 at one end thereof. The front can sealing portion 88 of theinner seal 14 may be configured to mate with the inner seal sealingportion 54 of the front can 24. The front can sealing portion 88 of theinner seal 14 may have a size that is slightly larger than the size ofthe inner seal sealing portion 54 of the front can 24. Thus, a pressfit, or an interference fit, may be provided between the inner seal 14and the front can 24. The press fit, or interference fit may provide asufficiently tight seal between the inner seal 14 and the front can 24,that no further sealing means is necessary. A suitable adhesive may beprovided between the inner seal 14 and the front can 24 to improve theseal formed therebetween. Such an adhesive may be applied whether or notthere is a press fit or interference fit between the inner seal 14 andthe front can 24, however, it can be of particular use in improving theseal in embodiments wherein there is not an press fit or interferencefit.

Referring to FIGS. 1 b and 1 c, the front can sealing portion 88 of theinner seal 14 may have a channel 89 therein that mates with theprojection 58 on the front can 24. The channel 89 may serve to positionthe inner seal 14 at a selected longitudinal position with respect tothe CV joint 10, which in turn ensures that the inner seal 14 ispositioned in a desired longitudinal position to perform the function ofinhibiting lubricant migration longitudinally towards the interior of CVjoint boot 12.

When the inner seal 14 mounts to the inner seal sealing portion 54 ofthe front can 24, the projection 58 may provide improved performance inthe seal achieved between the inner seal 14 and the inner seal sealingportion 54, relative to the seal that would be obtained without theprojection 58. An embodiment that would omit one or both of theprojection 58 and channel 62 would nonetheless be within the scope ofthe invention, however. A suitable adhesive could be provided to assistin the performance of the seal to inhibit lubricant migration into theboot 12. Such an adhesive could be used both in embodimentsincorporating the projection 58 and channel 62, and in embodiments thatdo not include a projection and channel.

The inner seal 14 may further include a flange portion 90 (see FIGS. 1 band 1 c), which is configured to engage a shoulder 91 on the front can24. The flange portion 90 and the shoulder 91 cooperate to position theinner seal 14 at a selected position with respect to the CV joint 10.The flange portion 90 and the shoulder 91 may be included whether or notthe projection 58 and channel 62 are provided.

Referring to FIG. 1 a, the inner seal body 86 has an optionalaccumulator portion 92, which is shaped to accumulate a quantity oflubricant 44 that would otherwise be urged to migrate towards the CVjoint boot 12. The accumulator portion 92 may have any suitable shapefor receiving and accumulating lubricant. For example the accumulatorportion 92 may be a generally C-shaped when viewed in a longitudinallyextending cross-sectional plane. In the embodiment shown in FIG. 1 a,the mouth of the C faces away from the axis A. The accumulator portion92 of the inner seal body 86 may be positioned immediately adjacent thefront can sealing portion BS of the inner seal body B6.

The inner seal body 86 includes a shield portion 93. The shield portion93 acts as a barrier to inhibit longitudinal flow of lubricant 44towards the CV joint boot 12. Furthermore, the shield portion 93 mayguide any encountered lubricant 44 outwards away from the axis A byvirtue of its slope angle A_(SH) with respect to the first shaft 16. Theshield portion 93 may, for example, be generally frusto-conical and mayhave a decreasing diameter in a direction towards the bearing 20. Theshield portion 93 may be positioned immediately adjacent and rearward ofthe accumulator portion 92 and may guide lubricant 44 thereto.

The shield portion 93 may end at a rear aperture 94 of the inner seal24. The rear aperture 94 should be at least sufficiently large as topermit the passage of the first shaft 16 therethrough.

During rotation of the CV joint 10, any lubricant 44 that escapes thebearing 20 will migrate generally outwardly away from the axis A and iscaught on the shield portion 93. Having a frusto-conical configurationincreases the likelihood that the lubricant 44 caught on the shieldportion 93 will migrate away from the aperture 94, thereby reducing therisk of the lubricant 44 inadvertently making its way into the interiorof the boot 12.

The radially inward end, shown at 95, of the shield portion 93 maycontact and form a seal with the bearing 20, and may thereby comprise abearing sealing portion. Preferably, the seal formed between the end 95of the inner seal 14 and the bearing 20 is formed with the inner race26, so that the shield portion 93 is configured to shield the boot 12from the entire open portion of the bearing 20. The open front portionof the bearing 20 is shown at 96, and is the portion between the innerface 56 of the outer race, and the outer face of the inner race 26. Theopen portion 96 is the portion of the bearing that holds lubricant 44.

Because of the rotation of the CV joint 10, a substantial portion of thelubricant 44 that migrates longitudinally out of the bearing 20 will doso proximate the inner surface 56 of the outer race 28. In analternative embodiment (not shown), the inner seal 14 can be configuredto shield only a radially outer portion of the open portion 96 of thefront 32 of the bearing 20. For example, the radially inner end 95 ofthe shield portion 93 may contact the cage 31 instead of contacting theinner race 26. In this alternative, lubricant 44 that escapes from thebearing 20 between the cage 31 and the outer race 28 can be blocked bythe shield portion 93. For applications wherein the lubricant 44 remainssufficiently viscous under the expected operating conditions for the CVjoint 10, a relatively small amount of lubricant 44 is likely to escapefrom the bearing 20 in the region between the cage 31 and the outer faceof the inner race 26.

In another alternative that is not shown, it is possible for the shieldportion 93 of the inner seal body 86 to not contact the bearing 20. Forexample, the shield portion 93 can have a free end that is positionednear the bearing but not in contact therewith. In this alternative, theshield portion can still capture lubricant that has migrated radiallyoutwardly and then frontwardly from the bearing 20 during rotation ofthe CV joint 10.

The inner seal 14 is preferably made sufficiently flexible toaccommodate relative angular or longitudinal movement in the CV jointbetween the first and second shafts. For example, the inner seal 14 maybe made from a similar material to the boot 12, so as to be flexible.The inner seal 14 may also include a hinge portion 98, which facilitatesflexure of the shield portion 93 relative to the rest of the inner seal14.

As shown in the embodiment in FIG. 1 a, the connection between the innerseal 14 and the front can 24 is entirely separate from the connectionbetween the front can 24 and the bearing 20, and is also entirelyseparate from the connection between the front can 24 and the boot 12.An advantage provided by the separate connection between the inner seal14 and the front can 24 is that it permits the inner seal 14 to beretrofit to an existing CV joint without requiring any modification ofthe existing elements, such as the front can 24. Additionally, itpermits a manufacturer to design and manufacture a single CV joint thatcan use the same front can 24 regardless of whether the inner seal 14 isprovided or not. This reduces inventory and other costs associated withhaving multiple designs for the front can.

Reference is made to FIG. 2 a, which shows a CV joint 100 and a combinedCV joint boot and inner seal 102 in accordance with another embodimentof the present invention. The CV joint 100 operatively connects thefirst and second shafts and includes the bearing 20 and a front can 104.

The front can 104 has a bearing sealing portion 106 that may be similarto the bearing sealing portion 48 (FIG. 1 a). The front can 104 mayfurther include a shield portion 108 that may be similar to the shieldportion 50 (FIG. 1 a). The front can 104 further includes a sealingportion 110 for receiving the combined boot and inner seal 102. Thesealing portion 110 may include a projection 112 which extends generallyradially inwardly towards the axis A from the front can inner surface,shown at 114. The sealing portion 110 may further include a crimpingportion 116, which is described further below.

The combined boot and inner seal 102 includes a boot portion 118 and aninner seal portion 120. The boot portion 118 inhibits entry of dirt anddebris from the exterior environment into the interior of the CV joint100. The boot portion 118 has a first or small end 121, at which is ashaft sealing portion 122 for mounting to the first shaft 16. The shaftsealing portion 122 may be similar to the shaft sealing portion 72 onthe boot 12 in FIG. 1, and may include a projection 124 that engages thechannel 74 in the first shaft 16. A holding means 126, such as anoetiker clamp, may be used to hold the first end 121 of the boot portion118 to the shaft 16.

The combined boot and inner seal 102 has a second or large end 127 atwhich is a front can sealing portion 128. The front can sealing portion128 mounts to and forms a seal with the front can 104 to inhibit leakageof lubricant 44 out to the exterior environment, and also inhibits entryof dirt and debris into the CV joint 100.

The front can sealing portion 128 may be made to have a press fit orinterference fit with the sealing portion 110 of the front can 104, toform a seal therewith. A suitable adhesive may be applied between thefront can sealing portion 128 and the sealing portion 110 to make up aportion of, or the entirety of, seal formed therebetween.

A channel 130 may be positioned on the front can sealing portion 128,which is adapted to receive the projection 112 on the front can 104. Thechannel 130 and projection 112 cooperate the channel 130 and projection112 may cooperate to position the front can sealing portion 128 of thecombined boot and inner seal 102 at a selected longitudinal positionwith respect to the CV joint 100. Additionally, they may make up aportion of the seal between the front can sealing portion 128 and thesealing portion 110.

It is alternatively possible for the projection 112 and channel 130 tobe omitted. Reference is made to FIG. 3, which shows a combined boot andinner seal 102′ and front can 104′ which are similar to the combinedboot and inner seal 102 and front can 104 respectively (see FIG. 2 a),except that the combined boot and inner seal 102′ and front can 104′ donot include cooperating projections or channels in their mating surfacesthat are part of their respective sealing portions, shown at 128′ and110′ respectively.

Referring to FIG. 2 a, the front can sealing portion 128 of the combinedboot and inner seal 102 may further include a flange portion 132 thatextends generally radially outwards, for engagement with the crimpingportion 116 on the front can 104. The crimping portion 116 can becrimped over the flange portion 132 to form the assembly shown in FIG. 2b. Once the crimping is completed, the flange portion 132 and thecrimping portion 116 cooperate to retain the front can sealing portion128 of the combined boot and inner seal 102 at a selected longitudinalposition with respect to the CV joint 100. Additionally, they may form aportion of, or the entirety of, the seal between the front can sealingportion 128 and the sealing portion 110.

The inner seal portion 120 inhibits the migration of lubricant 44 fromthe bearing 20 into the boot portion 118. The inner seal portion 120 mayinclude an optional accumulator portion 134, which may be similar to theaccumulator portion 92 on the inner seal 14 shown in FIG. 1 a. The innerseal portion 120 includes a shield portion 136, which may be similar tothe shield portion 93 on the inner seal 14 shown in FIG. 1 a.

Reference is made to FIG. 4, which shows the CV joint 138 in accordancewith another embodiment of the present invention. The CV joint 138 maybe similar to the CV joint 10 (FIG. 2 a). A combined boot and inner seal140 may be provided to protect the CV joint 138. The combined boot andinner seal 140 may be similar to the combined boot and inner seal 102(FIG. 2 a), and may include the boot portion 118 and the front cansealing portion 128. However, the combined boot and inner seal 140includes an inner seal portion 142 instead of the inner seal portion 120(FIG. 2 a). The inner seal portion 142 inhibits the migration oflubricant 44 from the bearing 20 into the boot portion 118. The innerseal portion 142 includes a shield portion 144, which extends from theinner surface of the front can 104 all the way to the first shaft 16.The inner seal portion 142 further includes a second first shaft sealingportion 146, which forms a second seal with the first shaft 16 toinhibit migration of lubricant therebetween. Though not necessary, it ispreferable that the seal formed between the shaft sealing portion 146and the shaft 16 is maintained in all possible relative positionsbetween the first and second shafts during operation of the CV joint138. The inner seal portion 142 may be configured in several differentways to maintain the seal. For example, the inner seal portion 142 mayinclude a sufficient amount of excess material between the front cansealing portion 128 and the shaft sealing portion 146 to accommodaterelative longitudinal movement between the first and second shafts, andto also accommodate angular movement therebetween. The boot portion 118has a first or small end 121, at which is a first shaft sealing portion122 for mounting to the first shaft 16.

Alternatively, the shaft sealing portion 146 may be sized to permitsliding movement relative to the first shaft 16, while still maintaininga seal therewith.

The inner seal portion 142 may thus be configured to block substantiallyall lubricant 44 from reaching the boot portion 118. The use of a shieldportion that extends all the way to the first shaft 16, and a shaftsealing portion for forming a seal with the first shaft 16, provides theinner seal portion 142 with the capacity to inhibit longitudinalmigration of lubricant 44 into the boot portion 118 even when thelubricant 44 is relatively non-viscous. For example, the lubricant 44may lose viscosity under increased temperatures, or simply as a resultof age. When the viscosity of the lubricant 44 is reduced, some of thelubricant 44 may leave the bearing 20 under the force of gravity, whilethe CV joint 138 is at rest, and come to rest on the first shaft 16.When the CV joint 138 is next operated, the lubricant 44 that had beenon the shaft 16 could be thrown outwardly towards the boot portion 118,or could by some other means continue to migrate longitudinally towardsthe boot portion 118. Even lubricant 44 that migrates along the shafthowever, is inhibited from reaching the boot portion 118, however, bythe shaft sealing portion 146 and inner seal portion 142.

The shield portion 144 and the shaft sealing portion 146 may beincorporated into the inner seal 14 to replace the shield portion 93 inthe embodiment shown in FIG. 1 a.

Reference is made to FIG. 5, which shows a CV joint 148 with the CVjoint boot 12 and an inner seal 150 made in accordance with anotherembodiment of the present invention. The CV joint 148 may be similar tothe CV joint 10 (FIG. 1 a), except that the CV joint 148 includes afront can 152 instead of the front can 24 (FIG. 1 a). The front can 152includes a crimping portion 154 that is configured to be crimped overthe front end 156 of the inner seal 150. to retain the inner seal 150 inposition and to assist in the seal obtained therebetween to inhibitmigration of lubricant 44 into the boot 12.

Reference is made to FIG. 6. Prior to crimping, the inner seal 150 maybe positioned at a selected longitudinal position with respect to the CVjoint 148 by means of a projection 158 and a cooperating channel 160 onthe front can 152 and the inner seal 150 respectively. Adhesive mayoptionally be used to adhere the inner seal 150 and front can 152together and to assist in forming a seal therebetween.

Referring to FIG. 5, once the inner seal 150 is positioned in the frontcan 152, the crimping portion 154 can be crimped over the front end 156of the inner seal 150. The boot 12 can then be mounted onto the frontcan 152 in similar fashion to the mounting of the boot 12 onto the frontcan 24 in the embodiment shown in FIG. 1 a.

In the embodiment shown in FIGS. 5 and 6, the inner seal 150 includes ashield portion 162 and a shaft sealing portion 164, which togetherinhibit lubricant 44 migration over the entire cross-sectional areabetween the inner surface of the front can 152 and the first shaft 16towards the boot 12. The shield portion 162 and the shaft sealingportion 164 may be similar to the shield portion 144 and the shaftsealing portion 146 in the embodiment shown in FIG. 4.

In the embodiments shown in the figures, the front can is shown to bedirectly connected to the bearing. It is alternatively possible for thefront can to be indirectly connected to the bearing, such that whateverconnects the front can to the bearing inhibits leakage of lubricant outof the CV joint, and inhibits entry of dirt and debris into the interiorof the CV joint.

In the positions shown in the figures, the CV joint, the boot or bootportion, the inner seal or inner seal portion and the first and secondshafts are all in alignment such that they all centered about thelongitudinal axes A and B. During operation, however, certain of thesecomponents may be positioned at a non-zero angle with respect to otherof these components. Nonetheless, for the purposes of this invention,all of these components can still be said to centered about or along thelongitudinal axes A and B even when they are positioned at a non-zeroangle with respect to each other.

As will be apparent to persons skilled in the art, various modificationsand adaptations of the apparatus described above may be made withoutdeparture from the present invention, the scope of which is defined inthe appended claims.

1. A combined CV joint boot and inner seal for mounting to a CV joint,the CV joint including a bearing, a back sealing means and a front canand having a CV joint longitudinal axis, wherein the bearing operativelyconnects a first shaft and a second shaft, the bearing has an inner raceand an outer race and has a front and a back, wherein the first shaft isconnected to the inner race and wherein the second shaft is connected tothe outer race, and wherein the front can is connected to the outerrace, the back sealing means seals against leakage of lubricant from theback of the bearing, the combined CV joint boot and inner sealcomprising: a boot portion having a first end and a second end andhaving a shaft sealing portion at the first end for sealing with thefirst shaft; a front can sealing portion for sealing with an inner sealsealing portion of the front can, wherein the front can sealing portionis positioned at the second end of the boot portion; and an inner sealportion, wherein, in use, the inner seal portion extends generallyinwardly towards the CV joint longitudinal axis from the front cansealing portion to block lubricant from migrating into the interior ofthe boot portion.
 2. A combined CV joint boot and inner seal as claimedin claim 1, wherein, in use, the innerseal portion extends bothlongitudinally towards the bearing and generally inwardly towards the CVjoint longitudinal axis from the front can sealing portion.
 3. Acombined CV joint boot and inner seal as claimed in claim 1, wherein theinner seal portion includes an accumulator portion for accumulatinglubricant that escapes from the bearing.
 4. A combined CV joint boot andinner seal as claimed in claim 1, wherein the inner seal portionincludes a bearing sealing portion for sealing with respect to the innerrace of the bearing.
 5. A combined CV joint boot and inner seal asclaimed in claim 1, wherein the inner seal portion includes a secondshaft sealing portion for forming a seal with the first shaft forinhibiting migration of lubricant from the bearing therebetween.
 6. Acombined CV joint boot and inner seal as claimed in claim 5, wherein theshaft sealing portion is sized to permit relative sliding movementbetween the shaft sealing portion and the first shaft.
 7. A combined CVjoint boot and inner seal as claimed in claim 1, wherein the inner sealportion includes a flange portion positioned to engage a shoulder on thefront can to position the inner seal portion at a selected longitudinalposition with respect to the CV joint.
 8. A combined CV joint boot andinner seal as claimed in claim 1, wherein the front can has an innersurface and includes a projection that extends inwardly towards the CVjoint longitudinal axis, and wherein the inner seal portion has achannel for engaging the projection.
 9. A combined CV joint boot andinner seal as claimed in claim 8, wherein the projection and channel aremutually engageable to form at least a portion of the seal between thefront can sealing portion and the front can.
 10. A combined CV jointboot and inner seal as claimed in claim 1, wherein, in use, theconnection between the front can sealing portion and the front can isentirely separate from the connection between the front can and theouter race.
 11. A combined CV joint boot and inner seal as claimed inclaim 1, wherein the front can sealing portion has a size relative tothe inner seal sealing portion of the front can to establish aninterference fit therebetween, the interference fit serving to inhibitthe migration of lubricant from the bearing therebetween.
 12. Acombination for use with a CV joint, wherein the CV joint includes abearing and a back sealing means and has a CV joint longitudinal axis,wherein the bearing operatively connects a first shaft and a secondshaft, wherein the bearing has an inner race and an outer race and has afront and a back, wherein the first shaft is connected to the innerrace, and wherein the second shaft is connected to the outer race,wherein the back sealing means seals against leakage of lubricant fromthe back of the bearing, the combination comprising: a front can,wherein the front can is connectable to the outer race, wherein thefront can has an outer surface and an inner surface and wherein thefront can has a crimping portion; and a combined CV joint boot and innerseal including a boot portion having a first end and a second end andhaving a shaft sealing portion at the first end for sealing with thefirst shaft, wherein the boot portion has an interior, wherein thecombined CV joint boot and inner seal further includes a front cansealing portion for forming a seal with an inner seal sealing portion ofthe front can, wherein the front can sealing portion is positioned atthe second end of the boot portion, wherein the front can sealingportion includes a flange portion, wherein the crimping portion iscrimped over the flange portion, wherein the combined CV joint boot andinner seal further includes an inner seal portion, and wherein the innerseal portion is extendible generally inwardly towards the CV jointlongitudinal axis from the front can sealing portion to block lubricantfrom migrating into the interior of the boot portion.
 13. A combinationas claimed in claim 12, wherein the contact between the crimping portionand the flange portion forms the seal.
 14. A combination as claimed inclaim 12, wherein the front can sealing portion has a size relative tothe inner seal sealing portion of the front can to establish aninterference fit therebetween, the interference fit serving to inhibitthe migration of lubricant from the bearing therebetween.